Materials Science

On track for a 100% bio-based plastic bottle

David Sudolsky, President & CEO of Anellotech, explains how his company’s thermal catalytic biomass conversion technology is helping to make 100% bio-based plastic bottles a reality.

Renewable materials for sustainable development

The past 3 years have been the hottest on record, and the UN’s World Meteorological Organization (WMO) confirms that this is predominantly caused by man-made climate change. It has become clearer than ever that companies need to be part of the solution to provide increasingly renewable options as alternatives to carbon-intensive, petro-based products. According to the European Bank for Reconstruction and Development (EBRD), a bio-based economy based on renewable materials could tackle climate change, with its mitigation potential estimated at 2.5 billion tons CO2-equivalent per year by 2030.

While the packaging industry has made strides in reducing its carbon footprint, some areas still need improvement. For example, approximately 54 million tons of widely sought-after polymer polyethylene terephthalate (PET) is manufactured globally. According to IHS Markit, PET usage in beverage bottles is expected to grow over 5% per year over the next 5 years – and most PET produced will still be petro-based.

Consumers and brand owners are demanding more products made from sustainable resources and many companies are seeking to meet this growth more renewably. Sustainable technology company Anellotech was founded in 2008 for this purpose and the company is aiming to create 100% bio-based drop-in aromatic chemicals from non-food biomass, often seen as a challenge due to a lack of efficient, cost-competitive and scalable processes. However, Anellotech’s thermal catalytic biomass conversion Bio-TCat technology is helping that goal become a reality.

Cost-competitive renewable chemicals from non-food biomass

Bio-TCat is a one-reactor catalytic process Anellotech jointly-developed with its R&D partners IFPEN and Johnson Matthey. Currently using wood as feedstock, in the future other biomass (corn stover, bagasse and other non-food materials) can be dried and ground. The biomass is rapidly heated, and the resulting gases are immediately converted into hydrocarbons by a reusable, sand-like zeolite catalyst. The resulting mixture of benzene, toluene and xylenes (BTX) is identical to petroleum-derived counterparts and can be further purified and separated by using well-known commercial technologies at either grassroots or existing petrochemical infrastructures.

Bio-TCat performs all process reactions in one fluid bed reactor, where biomass is thermally broken down and then catalytically converted into BTX. This single-step process uses a cost-effective catalyst jointly developed with Johnson Matthey to produce bio-based BTX in commercially-attractive yields.

By going directly from biomass to BTX in one step, the technology avoids highly-oxygenated bio-oil intermediate products, often seen in multi-step pyrolysis processes, thereby avoiding the need to add significant amounts of costly hydrogen, a byproduct stream that Anellotech plans to burn to generate electricity or that could alternatively be converted to a renewable source of hydrogen via a water-gas shift reactor.

100% bio-based bottles coming soon

Bio-based BTX is currently being produced at Anellotech’s 7-story tall TCat-8 pilot plant in Silsbee, Texas, from loblolly pine. These chemicals can be used in a range of chemical and commodity plastics applications such as polyester, polystyrenes, polycarbonates, nylons and polyurethanes, which are subsequently used to manufacture consumer goods such as food packaging, clothing, footwear, carpeting, automotive and electronic components, as well as beverage bottles.

Global beverage company Suntory has partnered with Anellotech to advance the development and commercialization of cost-competitive aromatics including bio-paraxylene – the key component needed to make 100% bio-based PET bottles, a dream chased by many in the bio-based industries. Suntory is currently using 30% plant-derived materials for its Mineral Water Suntory Tennensui brands. Both companies want to go further and create a 100% bio-based PET bottle through this alliance, part of a joint commitment to sustainable business practices.

Work is progressing and the first shipment of BTX has now been sent to partners IFPEN and Axens for purification studies of bio-paraxylene. BTX will be used to make renewable PET resin for prototype bottle manufacture and product testing. The first steps towards making prototype bottles have already begun.

Creating bio-based aromatics from renewable materials will dramatically alter the basic raw material sourcing for a wide range of consumer goods with important sustainability implications for society.

If industry can ensure performance, delivery and quality, the renewable chemicals sector will help take bio-based chemicals into the mainstream and make a tangible difference in mitigating climate change.